Method of increasing the capacity of rubber-lined centrifugal pumps and the pumps resulting therefrom



3,381,617 -LINED May 7, 1968 H. E. WRIGHT METHOD OF INCREASING THE CAPACITY OF RUBBER CENTRIFUGAL PUMPS AND THE PUMPS RESULTING THEREFROM Filed may 31, 196e 2 Sheets-Sheet l F/GA` 2.

UNMODIFIED CONVENTIONAL.

CONSTRUCTION 4 INVENTOR.

MODIFIED CONSTRUCTION HAROLD E. WRIGHT BY MLLNCKHODT 8 MALL/VKROT ATTORNE YS 3,381,617 METHOD oF INCREASING THE CAPACITY 0F RUBBER-UNED May 7, 1968 H. E. WRIGHT CENTRIFUGAL PUMPS AND THE PUMPS RESULTING THEREFROM 2 Sheets-Sheet 2 Filed May 31, 196e INVENTOR.

E. WRIGHT HAROLD BY MALL/NCKRODT MALL/NCKROT AT TORNE YS United States Patent O 3,381,617 METHOD OF INCREASING THE CAPACITY F RUBBER-LINE!) CENTRIFUGAL PUMPS AND THE PUMPS RESULTING THEREFROM Harold E. Wright, Salt Lake City, Utah, assignor to The Galigher Company, Salt Lake City, Utah, a corporation of Utah Filed May 31, 1966, Ser. No. 553,979 4 Claims. (Cl. 10S- 103) ABSTRACT OF THE DISCLOSURE A method of rebuilding and of thereby increasing the capacity of a conventional rubber-lined centrifugal pump having casing sections bolted together in face-to-face relationship to define a pumping chamber and a pressure discharge opening, one of the casing sections being provided with a suction inlet. The casing sections are separated and reassembled after inserting a rubber-faced expander member therebetween to provide an enlarged pumping chamber and discharge opening. The impeller is either modiiied by increasing blade size or replaced by an impeller whose blade size is correlated with the enlarged pumping chamber. The suction intake is also increased in size by replacing it with one of larger diameter and fastening it to the customary reinforcement ribs on the exterior of the pump facing. The rubber lining of the new suction inlet may either be vulcanized to the old rubber lining of the pumping chamber or may be provided by a corresponding portion of a replacement lining for the entire pump. The resulting pump constitutes part of the invention.

The invention relates to rubber-lined centrifugal pumps and is particularly concerned with providing a method of increasing the capacity of such pumps by structural changes that produce structurally different pumps.

Frequently, after a pump has been installed the flow characteristics of the system in which it is included are changed and it becomes necessary or desirable that a larger capacity pump be used. In the past this has generally meant that the smaller capacity pump had to be removed and a larger capacity replacement pump installed, usually at great expense, not only in the cost of the larger pump but because a new drive unit to accommodate the different pump has been required.

I have found that rubber-lined centrifugal pumps, such Vas those manufactured and sold by The Galigher Company, Salt Lake City, Utah, under the trademark Vacseal, can be modified to handle considerably larger volumes of material. The result is that there need be no pump or drive replacement.

In the making of the present invention it was an object to provide a method of structurally enlarging rubberlined centrifugal pumps, so that greater volumes of material can be pumped without requiring new drive equipment therefor.

In carrying out the method of the invention, the casing sections making up the pumping chamber and pressure discharge opening of a conventional rubber-lined centrifugal pump are unbolted and separated, a rubber faced expander member is inserted between the casing sections and they are reassembled to provide a pumpk having an enlarged discharge opening and an enlarged pumping chamber. An enlarged impeller is provided, or, if desired, the blades on the existing impeller can be built up until the necessary close tolerance between impeller and casing is obtained to insure continued eicient pumping. The size of the intake opening is increased by fitting a tubular adapter section and into an opening provided by ice removal of the original suction inlet, and the tubular adapter section is secured in place by fastening it to the customary reinforcement ribs on the exterior of the pump casing. A rubber liner inside the adapter section is vulcanized to the liner inside the suction end casing of the pump to insure an adequate seal or a replacement liner having an intake portion of larger diameter is installed.

There is shown in the accompanying drawings a specific embodiment of the invention representing what is presently regarded as the best mode of carrying out the generic concepts in actual practice. From the detailed description of this presently preferred form, other more specific objects and features will become apparent.

In the drawings:

FIG. l is a view in perspective of a conventional, rubber-lined, centrifugal `pump and its power unit before modification in accordance with this invention;

FIG. 2, a vertical section taken on the line 2-2 of FIG. 1;

FIG. 3, a View corresponding to that of FIG. 2, but showing the pump as modified in accordance with the invention;

FIG. 4, a vertical section taken on the line 44 of FIG. 3;

FIG. 5, a front elevation of the modified pump; and

FIG. 6, a fragmentary view in vertical section showing another embodiment.

Referring now to the drawings:

In FIGS. l and 2 there is shown at 10 a rubber-lined centrifugal pump of the type to be modified in accordance with the present invention.

Pump 10 is of split-case construction and has a driveend casing section 11 and a suction-end casing section 12, interconnected by a pair of central casing sections 13 and 14, which, together with casing sections 11 and 12, define a pumping chamber 10a and a pressure discharge opening 10b.

A replaceable liner 15, comprising a rubber covering 15a that is bonded to a backing plate 15b, tits within casing section 11. A similar replaceable liner 16, comprising a rubber covering 16a and a backing plate 16b, lits within casing section 12. The replaceable liners are held securely against their respective casing sections by stub bolts 17 that protrude from the backing plates through the casing sections and by nuts 18 that are threaded onto the stub bolts.

The central casing sections 13` and 14 form backing plates for rubber liners 19 and 20, respectively, and respectively include peripheral anges 21 and 22.

As illustrated in FIGS. l and 2, in the usual pump construction the flanges 21 and 22 are bolted together with portions of the rubber liners 19' and 20 therebetween to serve as seals. The central casing sections are then fitted inside the drive-end and suction-end casing sections and are bolted to them by stub bolts 23. Such bolts protrude from the central casing sections through the drive-end and suction-end casing sections and have nuts 24 threaded thereon.

As so assembled, the rubber liners 19 and 20 of the central casing sections abut the rubber coverings 15a and 16a, respectively, to form seals between the casing Sections.

An impeller shaft 25 extends through drive-end casing section 11 and has an impeller 26 fixed on its end inside the casing sections. The impeller has rubber covered blades 27 projecting therefrom that extend to within a very close tolerance of the rubber covering 16a of the suction-end casing section 12. The impeller shaft is passed through bearings 28, FIG. l, that rest on support 29, and is driven by motor 30 (also mounted on support 29) through pulley 31, belt 32 and pulley 33. Gland 34 is employed to provide a seal between the impeller shaft 25 and the drive-end casing section.

The intake 10c to the pump is provided through the center of suction-end casing section 12, and the rubber covering 16a extends into the opening and is bonded to a cylindrical backing sleeve 35` that has stub-bolts 36 protruding therefrom through a ring-shaped portion 12a of the suction-end casing section. Nuts 37, threaded onto the stub-bolts, secure the rubber covering in place.

Radiating ribs 38 are integral with and serve as buttressing reinforcements n the face of the suction-end casing section and extend outwardly from the ring-shaped portion 12a.

In operation, motor 30 drives the impeller shaft 2S to rotate impeller 26. Material being pumped is then drawn in through the pump intake c and is discharged, under pressure, through outlet 10b formed by matched tangential extensions 39 of the central casing sections.

In accordance with the present invention the capacity of pump 10 can be greatly increased, without the need for new casing sections or a new drive unit. Thus, as is best seen in FIGS. 3-5, in carrying out the method the casing sections are unbolted and pulled apart, as in the instance of changing a liner 15 or 16. A spacer 40 is then inserted between the anges 2.1 and 22 to increase the size of the pumping chamber, see 41, FIG. 3, formed by the central casing sections. This spacer has the same general shape as the abutted peripheral edges of the central casing sections and is coated with rubber 40a on at least its inner annular face, so that, when the central casing sections are bolted to the spacer, a tight seal is formed and the exposed inner face of the pumping chamber remains fully lined with a rubber covering. The spacer also separates the matched tangential extensions 39 of the central casing sections to increase the size of the discharge opening from the pump.

Once the pump chamber has been enlarged, the irnpeller is changed to substitute one having longer blades, or the existing impeller is built-up by vulcanizng additional rubber on the blade tips until the close tolerance between the blades and the suction end casing section necessary for eicient pumping is obtained.

With the increase in size of pump chamber, impeller, and discharge opening it is necessary to increase the size of the suction intake opening. This is accomplished by cutting away the ring-shaped portion 12a of the suctionend casing section 12 and replacing the replaceable lining 16 thereof with one having a backing ring 45 that yforrns a tubular inlet opening 'and that has brackets 46 adapted to be bolted, as by bolts 47 passed through holes drilled in ribs 38, to the webs. Alternatively, as shown in FIG. 6, a backing ring 48 can be used and a rubber lining 49 inside the ring can be vulcanized to the existing liner after the part of liner 16 that is xed to portion 35 has been cut away. The backing ring 48 is then bolted to the ribs 38.

The same drive unit, including bearings 28 for the impeller shaft and the motor, can be used to drive the increased capacity pump. In one test operation it was found that over a ve month operation period $3,500.00 was saved by changing a pump capacity in accordance with this invention and using the existing drive unit, instead of installing and using a new, larger capacity pump for the same period of time.

Whereas this invention is here described and illustrated with respect to a certain form thereof, it is to be understood that many variations are possible without departing from the subject matter particularly pointed out in the following claims, which subject matter I regard as my invention.

I claim:

1. A method of rebuilding and of thereby increasing the capacity of a rubber-lined, centrifugal pump having intermediate and opposite-end casing sections removably secured together in face-to-face relationship to dene a pumping chamber and a pressure discharge opening, one of the end casing sections being provided with a ribbuttressed, central, ring portion deiining a suction inlet, comprising separating the casing sections which define the pumping chamber and pressure discharge opening;

inserting a rubber-surfaced expander of appropriate thickness between the separated casing sections to increase the size of the pumping chamber and of the pressure discharge opening;

increasing the lengths of the impeller blades of the pump to provide requisite close tolerance between such blades and the opposite end casing section;

cutting away the ring portion of the said one end casing section;

replacing said ring portion with a corresponding ring of appropriately larger diameter provided with outwardly extending brackets corresponding to the buttressing ribs of the said one end casing section;

securing said brackets to the respective buttressing ribs;

providing for said replacement ring a rubber lining and integrated With the rubber lining of the pump; securing the said separated casing sections together Y about the expander insert.

2. A method according to claim 1, wherein the size of the impeller blades is increased by adding material thereto to increase their lengths in the direction of the opposite end casing section.

3. A rebuilt, rubber-lined, centrifugal pump, comprising intermediate and opposite-end casing sections and a rubber-surfaced expander insert secured together in face-to-face relationship to define enlarged pump chamber and pressure discharge opening;

one of the end casing sections being provided with a central orifice as a suction inlet;

a pump impeller having blades extending into appropriately close tolerance with the opposite end casing section;

said one end casing section having a series of radial ribs projecting outwardly therefrom and surrounding said suction inlet;

a ring having outwardly extending brackets corresponding to said ribs and secured thereto, holding said ring in close registry with said suction orifice and defning a tubular suction inlet for the pump;

and a rubber lining for said ring integrated with the rubber lining of the pump.

4. A rebuilt centrifugal pump in accordance with claim 3, Awherein the blades of the pump impeller have builtup sections at their ends, increasing their length in the direction of the opposite end casing section.

References Cited UNITED STATES PATENTS 765,969' 7/ 1904 tI-Ianson 103-1013 1,271,072 7/1918l Parsons 10S-114 3,123,284 3/ 1964 Greenawalt 230-133 3,165,257- 1/ 1965 Edwards 230\-133 3,257,956 6/ 1966 Logue et al 10B-114 FOREIGN PATENTS 110,760 6/1940 Australia.

v 613,892 12/1948` Great Britain.

863,361 3/ 1961 Great Britain.

HENRY F. IRADiUAZO, Primary Examiner. 

